aheu

Finally I identified my issue. The small red and white wire were loose. I asked a friend to soldered them back on and now everything is fine. Thank you all for you recommendations!

Of course, I have read the recommendations in the artikel regarding the similar topic for the UM3. I adjusted the leveling screws, I did several manual bed leveling procedures, a firmware update, but unfortunately nothing changed. Perhaps it is a UM S5 specific issue...

Automatic bed leveling failed: Difference between detected height of both print cores exceeds realistics values. I did a manual bed leveling procedure, but got the same error message. Can anybody help me?